I don't totally agree with your definition. Lean is about creating value as the customer defines value while cutting anything wasteful. Internal waste (process, objects, delays) and external waste. See Costs of Poor Quality. Lean could be removing wasteful process steps but Ries removed important process steps. He makes product-market fit sound like asking people questions with no attention to what good or wasteful bad questions are. If you remove value-creating or value-ensuring steps, you created waste.